In enzymology, an inositol-tetrakisphosphate 1-kinase ( EC 2.7.1.134) is an enzyme that catalyzes the chemical reaction

ATP + 1D-myo-inositol 3,4,5,6-tetrakisphosphate ${\displaystyle \rightleftharpoons }$ ADP + 1D-myo-inositol 1,3,4,5,6-pentakisphosphate

Thus, the two substrates of this enzyme are ATP and 1D-myo-inositol 3,4,5,6-tetrakisphosphate, whereas its two products are ADP and 1D-myo-inositol 1,3,4,5,6-pentakisphosphate.

This enzyme belongs to the family of transferases, specifically those transferring phosphorus-containing groups ( phosphotransferases) with an alcohol group as acceptor. The systematic name of this enzyme class is ATP:1D-myo-inositol-3,4,5,6-tetrakisphosphate 1-phosphotransferase. Other names in common use include 1D-myo-inositol-tetrakisphosphate 1-kinase, inositol-trisphosphate 6-kinase, 1D-myo-inositol-trisphosphate 6-kinase, ATP:1D-myo-inositol-1,3,4-trisphosphate 6-phosphotransferase, inositol-trisphosphate 5-kinase, 1D-myo-inositol-trisphosphate 5-kinase, and ATP:1D-myo-inositol-1,3,4-trisphosphate 5-phosphotransferase. This enzyme participates in inositol phosphate metabolism and phosphatidylinositol signaling system.

Structural studies

As of late 2007, 3 structures have been solved for this class of enzymes, with PDB accession codes 2ODT, 2Q7D, and 2QB5.

References

• Stephens LR, Hawkins PT, Morris AJ, Downes PC (1988). "L-myo-inositol 1,4,5,6-tetrakisphosphate (3-hydroxy)kinase". Biochem. J. 249 (1): 283–92. doi: 10.1042/bj2490283. PMC  1148695. PMID  2829850.
• Balla T, Guillemette G, Baukal AJ, Catt KJ (1987). "Metabolism of inositol 1,3,4-trisphosphate to a new tetrakisphosphate isomer in angiotensin-stimulated adrenal glomerulosa cells". J. Biol. Chem. 262 (21): 9952–5. PMID  3497156.
• Shears SB, Parry JB, Tang EK, Irvine RF, Michell RH, Kirk CJ (1987). "Metabolism of D-myo-inositol 1,3,4,5-tetrakisphosphate by rat liver, including the synthesis of a novel isomer of myo-inositol tetrakisphosphate". Biochem. J. 246 (1): 139–47. doi: 10.1042/bj2460139. PMC  1148250. PMID  2823793.
• Shears SB (1989). "The pathway of myo-inositol 1,3,4-trisphosphate phosphorylation in liver. Identification of myo-inositol 1,3,4-trisphosphate 6-kinase, myo-inositol 1,3,4-trisphosphate 5-kinase, and myo-inositol 1,3,4,6-tetrakisphosphate 5-kinase". J. Biol. Chem. 264 (33): 19879–86. PMID  2584198.
• Yang X, Shears SB (2000). "Multitasking in signal transduction by a promiscuous human Ins(3,4,5,6)P(4) 1-kinase/Ins(1,3,4)P(3) 5/6-kinase". Biochem. J. 351 (Pt 3): 551–5. doi: 10.1042/0264-6021:3510551. PMC  1221393. PMID  11042108.
• Vogel G, Riley AM, Potter BV, Shears SB (2002). "Regulation of Ins(3,4,5,6)P(4) signaling by a reversible kinase/phosphatase". Curr. Biol. 12 (6): 477–82. doi: 10.1016/S0960-9822(02)00713-3. PMID  11909533. S2CID  14548016.